Field of the Invention
This invention relates to a new and improved method and apparatus to clean debris from eyelids, to treat blepharitis, and to prevent meibomian gland obstruction, which method and apparatus permit self-administered eyelid cleaning and treatment.
Description of Related Art
“Dry eye” is the world's most common eye disease. “Dry eye” indicates the lack of quantity and/or quality of the tear film. In the human eye, the tear film covering the ocular surfaces is composed of three layers. The innermost layer in contact with the ocular surface is the mucus layer, comprised of many mucins. The middle layer, comprising the bulk of the tear film, is the aqueous (water) layer, and the outermost layer is a thin (less than 250 nm) layer (“lipid layer”) comprised of many lipids. The typical upper eyelid has about 25 meibomian glands and the lower eyelid has about 20 meibomian glands. The meibomian gland orifices open onto the eyelid margin at and around the junction of the inner mucous membrane and the outer skin of the eyelids; that junction is termed the mucocutaneous junction.
The upward phase of blinking causes the upper eyelid to pull a sheet of the lipids secreted by the meibomian glands upward and over the other two layers of the tear film, thus forming a type of protective coating which limits the rate at which the underlying layers evaporate. Thus, a defective lipid layer or an incorrect quantity of such lipids can result in accelerated evaporation of the aqueous layer which, in turn, causes symptoms such as itchiness, burning, irritation, and dryness, which are collectively referred to as “dry eye”. When left untreated, the consequences of dry eye can be severe, and even result in loss of vision (e.g., from desiccation of the corneal epithelium, ulceration and perforation of the cornea, or an increased incidence of infectious disease).
Dry eye states have many etiologies. A common cause of dry eye states is a disorder in which the glands are obstructed or occluded, usually referred to as “meibomian gland dysfunction” (“MGD”). Meibomian gland dysfunction is frequently the result of keratotic obstructions which partially or completely block the meibomian gland orifices. Such obstructions compromise the secretory functions of the individual meibomian glands. More particularly, these keratotic obstructions can comprise combinations of bacteria, sebaceous ground substance, dead cells, and/or desquamated epithelial cells.
Additional causes of the dysfunction of the lipid layer are associated with eyelid margin inflammation (e.g., anterior and posterior blepharitis, hordeolum, sty, chalazion, and rosacea). The etiological factors of many of these inflammations include an overgrowth of bacteria (and/or parasites) and their toxic waste. These bacteria not only cause the lipid tear film to dysfunction, but they also destroy and block the very lipid-producing infrastructure by attacking the glands in the eyelid skin. Unfortunately, the particular types of bacteria and parasites that cause the inflammation/infections are common. The chance of having these on the eyelids is nearly 100%. In themselves, they are not dangerous, but it is the overgrowth and their toxic waste on the eyelid margin and the eyelashes that must be avoided. Allowing the bacteria and parasites to proliferate must be prevented, especially if one is diagnosed as a dry eye sufferer.
While the tear film operates as a singular entity and all of the layers are important, the lipid layer, which is secreted from the meibomian glands, is of particular significance as it functions to slow the evaporation of the underlying layers and to lubricate the eyelid during blinking; such slowing of evaporation and lubrication of the eyelid largely prevent “dry eye syndrome”.
Thus, to summarize, the meibomian glands of mammalian (e.g., human) eyelids secrete oils that prevent evaporation of the tear film and provide lubrication to the eye and eyelids. These glands can become blocked or plugged by various mechanisms leading to so-called “dry eye syndrome”. While not the only cause, meibomian gland dysfunction is a major cause of dry eye syndrome. Dry eye syndrome is characterized by a blockage of the meibomian glands, which prevents normal lipid secretions from flowing from the meibomian glands to form the lipid layer of the tear film.
Various treatment modalities have been developed to treat the dry eye condition, including drops which are intended to replicate and replace the natural tear film, and pharmaceuticals which are intended to stimulate the tear producing cells. Various heating devices are commercially available that are designed to assist in unclogging the meibomian glands by “melting” blockages of the meibomian glands. Other techniques involve manual expression of the glands and manual scrubbing of the eyelid margins.
Eye drops such as REFRESH®, SOOTHE® and SYSTANE® brand eye drops are designed to closely replicate the naturally occurring healthy tear film. However, their use and administration is merely a treatment of symptoms and not of the underlying cause. The effect of applying eye drops is short-lived. Further, the use of drops is generally for an indefinite length of time and consequently, extended use can become burdensome and costly.
Since dry eye is exacerbated by eyelid margin debris and bacterial overgrowth, daily eyelid hygiene is often prescribed by physicians and recommended by health institutions worldwide. This is for the life of the patient, because, as mentioned, dry eye is chronic, with no known cure: unless proper eyelid hygiene is instituted, dry eye syndrome will only worsen with age.
Herein lie the unsolved problems. No existing eyelid care device enables self-administered eyelid treatment using a motorized handpiece; all prior art motorized appliances are for clinical use. A second problem is the risk of patient injury during training of eyelid care professionals, and of lay persons who use a motorized eyelid care appliance for cleaning their own eyelids (“self-administered cleaning” or “SA Cleaning”) or for cleaning others' eyelids (“second party cleaning” or “SP Cleaning”). The “second party” can be a pet (blepharitis is common in dogs and cats). A third problem is that all prior art eyelid care devices with motorized handpieces use unidirectional rotary tools (aka “heads”) that become entangled with hair. A fourth problem is that eyelid care devices with rotary tools cause many patients to flinch when the tool first contacts the eyelid margin; such flinching increases the risk of contact by the tool with the cornea, sclera, or other parts of the eye and resulting laceration or other injury. A fifth problem is a lack of instrumentation of prior art motorized eyelid care devices, which instrumentation (e.g., proximity monitoring, cleaning efficacy) and features (e.g., safety shutoff) would enable safer use of an eyelid care device as well as data collection and analysis of clinical signs and efficacy of cleaning.
People tend to wash their face, but not their eyelids. Eyelid hygiene should optimally be performed on a daily basis for maximum efficacy and optimal hygiene. Currently only manual scrubbing methods with cloths or fingers is available for daily home use, but such manual methods are like brushing one's teeth with a washcloth. Just as brushing one's teeth with a washcloth does not clean the gingival sulcus or mesio-distal aspects of teeth, an eyelid scrub typically contacts only the anterior ciliary margin and does not clean the entire confluence of the mucosal surface of the conjunctiva and the cutaneous epithelium. Even though daily eyelid hygiene is critically important for patients with an eyelid disease, there is typically no compliance by patients for whom SA Cleaning is ordered by their ophthalmologist. Due to a lack of alternatives, “baby shampoo” and a washcloth or cotton-tipped swab is often recommended by ophthalmologists for a patient's SA Cleaning. This current “prescription” for eye hygiene has significant non-compliance issues, i.e., patients fail to perform SA Cleaning. For instance, in a “baby shampoo regimen”, the baby shampoo is mixed with warm or hot water in a prescribed ratio, and the solution is then applied with non-sterile applicators such as finger tips, cotton tips, or washcloths (typically, unsanitary).
Although commercial “eyelid scrubs” are available in several forms, such as impregnated, pre-moistened towelettes or pads, or as bottled cleansers applied to a non-sterile applicator pad or to fingertips, such eyelid scrubs do not improve patient compliance or efficacy. These rely on the individual to perform vigorous back and forth scrubbing of all four eyelid margins, which is cumbersome, time consuming, sometimes painful, and has uneven results . . . all of which are strong disincentives to observe a an eyelid cleaning regimen.
Preventive and therapeutic interventions need to be more easily implemented at an earlier age, or stage, of dry eye syndrome development to decrease the likelihood of chronically scarred and/or dysfunctional meibomian glands. Lack of patient compliance is further evidenced by way of disproportionate commercial sales for eye care products, which shows a clear indication that people simply do not clean their eyelids: in contrast to the US current eyecare market for eye drops (excluding contact lens solutions) of $1 billion, but eyelid scrubs show less than $8 million in retail sales.
Given existing art methods and devices, it is not surprising that there is little or no compliance to eyelid hygiene by patients. Related art describes an “Eyelid and Anterior Orbit Swab” (to Hamburg, U.S. Pat. No. 4,883,454) and various eyelid cleansers, such as U.S. Pat. Nos. 8,535,736, 8,449,928, and 8,231,912 (to Gilbard), to clean the eyelids, but these rely solely on manual back and forth motion of a device on the eyelid margin and manual application of a cleanser.
US Published Application No. 20070060988 (by Grenon) discloses an eyelid heater that “melts” plugs that block meibomian glands and expresses the melted plugs through meibomian gland openings on the eyelid margin. Unlike the instant invention, the Grenon device does nothing to actually clean the eyelid margin.
U.S. Pat. No. 8,523,928, (Korb and Grenon) describe a system for heating eyelids. This device is used to liquefy, express and evacuate ductal obstruction, not clean debris and biofilm from the lid margin. The Korb device does nothing to actually clean the eyelid margin.
Ophthalmologists presented with a particle (usually a metal particle) embedded in a patient's cornea or sclera (or with the “rust ring” left by a particle) typically use an ophthalmic burr, such as an Algerbrush (Alger Co., Inc., Lago Vista, Tex.) or Aaron Burr (Bovie Medical Corp., Purchase N.Y.) to “scrub” the particle or “rust ring” from the cornea or sclera. Ophthalmic burr devices typically have a motorized handpiece and detachable burrs (burr diameter in the 0.5 mm to 1.0 mm range). At least one eyelid cleaning device, the BlephEx® device described in US Published Patent Application Nos. 20140031845, 20140052164, and 20140214062, uses a design and unidirectional rotation virtually identical to that of ophthalmic burrs, but with a “sponge head” instead of a burr. Like ophthalmic burrs, the BlephEx® device drives a head with a full rotary motion and is for use by eyecare professionals. An “eyecare professional” is a person skilled in the art of ocular hygiene, such as ophthalmologists, optometrists, nurses trained in eyecare, and technicians trained in eyecare. The BlephEx® handpiece rotates a small sponge, is guided along the eyelid margin by an eyecare professional, removes scurf and debris, and exfoliates the eyelids. The key disadvantages of the Blephex® device are its “motorized swab” design, unidirectional spinning (rotating) head (as distinct from an oscillating head moving in a reciprocally arcuate path), lack of instrumentation, and lack of safety features. Using an oscillating head to clean eyelids has significant advantages over existing art eyelid cleaning devices. Oscillating devices tend to be safer than rotary devices; an oscillating head does not have the directional “kick” (i.e., start-up torque) of a rotating head, so there is less chance of a user losing control of the device, e.g., the device jumping out of the user's hand. For that reason, devices with oscillating heads are easier to control than rotary devices. An oscillating eyelid care device does not induce a flinch response in the subject when the head first contacts an eyelid. An oscillating head creates less flying debris than a rotary head, making an oscillating head a better choice for work in an area where excessive flying debris might be a nuisance, such as near the eye.
The BlephEx® device can only safely be used by an eyecare professional due to the ergonomics and dynamics (e.g., “motorized swab” form, flinch induction, unidirectional rotation) of the device. The stick-like design (i.e., cylindrical handpiece with long, rotating, longitudinally aligned head) of the BlephEx® device prevents the use of a BlephEx® device for SA Cleaning, i.e., for a patient to use in performing eyelid cleaning on him/herself. A device with a stick-like design must be used by a second person, typically by an eyecare professional.
In eyelid cleaning experiments in a dog model that compared the invention with (i) manual scrubbing, (ii) the Blephex® device, (iii) a heated, vibrating cup-like device similar to that described in U.S. Pat. No. 8,491,508 (to Smith), and (iv) with motorized cosmetic appliances, such as the Clarisonic Opal® (a discoid, lotion applicator that uses an oscillating, solid silicone head), the results revealed a significant decrease in eye discharge in eyes treated with the instant invention as compared to control and to the other devices. In all trials, the eyelid margins of one eye of a subject were not cleaned, and the eyelid margins of the other eye were cleaned. When compared to manual lid scrubs the instant invention removed lid discharge more quickly and thoroughly than the manual lid scrub product. The heated, vibrating, cup-like device did not clean debris from lid margins. Testing of the Blephex® device on dogs had to be discontinued because the Blephex® device induced a strong flinching response when applied to eyelid margins, and dog hair quickly became entangled in the head of the Blephex® device, which not only caused pain to the dogs but “reeled in” the Blephex® device, which caused erratic paths of the device while the head was still spinning. Dogs could not tolerate the vibration of the Clarisonic Opal® on their eyelids, and the Clarisonic Opal® with its smooth silicone head produced no detectable cleaning action. The cleaning results in the dog model showed the eyelid care appliance of the invention to be markedly superior, based on a close examination of the uncleaned eye versus the cleaned eye, and of cleaned eyes of all subjects. The same solvents and cleansers were used in all trials. The dog model trials were conducted under a research protocol which was reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) at the University of Hawaii. The assistance of a licensed veterinarian was obtained. Four dogs were given one treatment per week with the eyelid care appliance over a three week period. Due to hair entanglement and flinching response, treatment using the Blephex® device was aborted in the dog model after two treatments. Treatment using the Clarisonic Opal® was aborted during the first attempt at treatment, given the strong adverse reaction of the dogs to the Clarisonic Opal® device.
Existing powered eyecare devices have heads with a constant unidirectional rotation, which requires that the operator manually change the rotational direction (e.g., from clockwise to counterclockwise) of the head and retrace the path of cleaning to ensure efficient cleaning. An oscillating head provides better removal of debris and more uniform results than devices with unidirectional head rotation, which is the reason that oscillating heads are used in powered toothbrushes. The head of the driven attachment of a commercial, off-the-shelf powered toothbrush has a “brush head” and such driven attachment is called a “brush head attachment”. Clinical studies in the dental care literature have shown that powered toothbrushes with an oscillating brush head are significantly better in reducing plaque and gingivitis compared to a manual toothbrush and brushing technique, and also compared to powered rotary toothbrushes. Just as the oscillatory movement of a powered toothbrush brush head ensures better cleaning than manual scrubbing, because a brush head typically oscillates at about 7,000 to 9,000 strokes/minute, the oscillatory movement of a powered handpiece coupled to an eyelid care module ensures better cleaning than manual scrubbing of the eyelids. The following three publications report the comparative advantages of powered, oscillating head, toothbrushes.                A comparative study of plaque removing efficiency using rotary electric and manual toothbrushes.        Swed Dent J. 1991; 15:229-234.        Cochrane Database Syst Rev. 2005; 18(2):CD002281.        J Am Dent Assoc. 2003 September; 134(9):1240-4.        Manual versus powered toothbrushes: the Cochrane review.        Niederman R; ADA Council on Scientific Affairs; ADA Division of Science; Journal of the American Dental Association.        Source: DSM-Forsyth Center for Evidence-Based Dentistry, The Forsyth Institute, Boston, Mass. 02115, USA. rniederman@forsyth.org        CONCLUSIONS: Powered toothbrushes with a rotation-oscillation action achieve a significant, but modest, reduction in plaque and gingivitis compared with manual toothbrushes.        National Institutes of Health        Cochrane Database Syst Rev. 2005 Apr. 18; (2):CD002281.        Manual versus powered toothbrushing for oral health.        Robinson P G, Deacon S A, Deery C, Heanue M, Walmsley A D, Worthington H V, Glenny A M, Shaw W C.        Source: Department of Dental Public Health, School of Clinical Dentistry, University of Sheffield, Claremont Crescent, Sheffield, UK. peter.g.robinson@sheffield.ac.uk        CONCLUSIONS: Powered toothbrushes with a rotation oscillation action reduce plaque and gingivitis more than manual tooth brushing.        Powered/electric toothbrushes compared to manual toothbrushes for maintaining oral health—Cochrane Report June 2014.        Yaacob M, Worthington H V, Deacon S A, Deery C, Walmsley A, Robinson P G, Glenny A. This article reviews 56 studies published from 1964 to 2011 in which 5068 participants were randomised to receive either a powered toothbrush or a manual toothbrush. Majority of the studies included adults, and over 50% of the studies used a type of powered toothbrush that had an oscillation mode of action (where the brush head rotates in one direction and then the other, aka reciprocally arcuate).        CONCLUSIONS: The evidence produced shows benefits in using a powered toothbrush when compared with a manual toothbrush. There was an 11% reduction in plaque at one to three months of use, and a 21% reduction in plaque when assessed after three months of use. For gingivitis, there was a 6% reduction at one to three months of use and an 11% reduction when assessed after three months of use.        
One advantage of oscillating brush head, powered toothbrushes in general is their ability to remove a greater amount of plaque in a given period of time than manual brushes. One study (Preber H, Swed. Dent. J. 1991; 15:229-234) found that 75% of dental biofilm was removed in 15 seconds with an oscillating powered toothbrush; the same amount of plaque removal required twice as long with a manual brush. The results of more thorough cleaning process with oscillating powered toothbrushes can be extrapolated to eyelid hygiene using an oscillating powered device. However, powered toothbrushes cannot be easily adapted to eyelid care, given the large size of the handpiece, brush head attachment, and brush head, the stiff bristles on toothbrush brush heads (which would lacerate the eyelid margin, cornea, and sclera if used to clean eyelid margins), and the expense of disposable “necks” (the “neck” is the detachable distal portion of a powered toothbrush that terminates in a non-removable brush head, which means the entire neck must be discarded when the brush head wears, rather that disposal of only the brush head). Because powered toothbrush necks are not easily removed and are used for months before replacement, the brush heads become unsanitary. For sanitary eyelid care, the head of a device must be easily replaceable and inexpensive, or durable and autoclavable.
There is need for an eyelid care appliance that enables SA Cleaning, reduces risk of patient injury during training of eyelid care professionals, reduces risk of patient injury during SA Cleaning and SP Cleaning, provides an oscillating head, provides instrumentation and safety features that improve efficacy of eyelid care, provides an inexpensive and easily replaceable head (and alternatively, a durable and autoclavable head) and ideally provides an adjustable head angle and optionally provides control over oscillation frequency and angular sweep.
The eyelid care appliance described and claimed herein solves the proceeding problems by providing, in a preferred embodiment, an oscillating, detachable sponge head, adjustable head angle, an ergonomic powered handpiece, sensors and other controls and instrumentation (such as, controls, indicators, displays, video, and/or data transmission), and auxiliary functions (cleanser, solvent, and medicament dispensing, gas and liquid dispensing, heating, and suction) that improve professional eyelid care, SA Cleaning, and SP Cleaning.